To reproduce:
1. Open attached project "HLSLccShaderOpenGLES-LWRP.zip"
2. Build for Android
3. Observe the shader errors via Logcat

Expected: editor throwing errors due to unrecognized HLSL shader syntax
Actual: shader code is accepted by editor, but fails to be recognized in build, errors are thrown

Reproduced in: 2017.4.29f1, 2018.4.2f1, 2019.1.6f1, 2019.2.0b6, 2019.3.0a6

Note: logcat warnings (GLES3 supported):

06-11 14:26:23.256 32051 32216 D Unity : 0:191: L0002: Undeclared variable 'u_xlati9'
06-11 14:26:23.256 32051 32216 D Unity : Note: Creation of internal variant of shader 'Custom/TerrainRTTilePattern' failed.
06-11 14:26:23.256 32051 32117 D Unity : WARNING: Shader
06-11 14:26:23.256 32051 32117 D Unity : Unsupported: 'Custom/TerrainRTTilePattern' - Pass '' has no vertex shader
06-11 14:26:23.256 32051 32117 D Unity : ERROR: Shader
06-11 14:26:23.256 32051 32117 D Unity : Shader is not supported on this GPU (none of subshaders/fallbacks are suitable)
06-11 14:26:23.256 32051 32117 D Unity : WARNING: Shader
06-11 14:26:23.256 32051 32117 D Unity : Unsupported: 'Custom/TerrainRTTilePattern' - Setting to default shader.

logcat warnings (GLES3 not supported):

06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:134: '' : integer constant overflow
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:134: '' : integer constant overflow
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:134: '' : integer constant overflow
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:138: '&' : supported in pack/unpack shaders only
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:139: '&' : supported in pack/unpack shaders only
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:144: '&' : supported in pack/unpack shaders only
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:145: '&' : supported in pack/unpack shaders only
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:147: '' : integer constant overflow
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:147: '' : integer constant overflow
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:147: '' : integer constant overflow
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:147: '' : integer constant overflow
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:177: 'u_xlati9' : undeclared identifier
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:177: 'x' : field selection requires structure, vector, or matrix on left hand side
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 0:177: 'assign' : cannot convert from 'const int' to 'float'
06-11 08:48:27.084 21056 21123 D Unity : ERROR: 14 compilation errors. No code generated.

Reproduced on devices:
VLNQA00104, Lge Nexus 5 (Nexus 5), Android 6.0.1, CPU: Snapdragon 800 MSM8974, GPU: Adreno (TM) 330
VLNQA00270, Samsung Galaxy S10e (SM-G970F), Android 9, CPU: Exynos 9 9820, GPU: Mali-G76